The Lockheed rotor head
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From: Great South East, tired and retired
The Lockheed rotor head
https://www.youtube.com/watch?v=ycXEgIRWGqs&t=250s
Sorry I don't know how to bring up the YooChoob screen
Wonder why this rotor head design was never pursued? It seems to be a real winner, but the machines they attached it to were sunk by political and inter-service infighting.
AC, the thread at the top of the page Embedding YouTube videosis a good place to start!
Splot
***Theng, Smite!
Sorry I don't know how to bring up the YooChoob screen
Wonder why this rotor head design was never pursued? It seems to be a real winner, but the machines they attached it to were sunk by political and inter-service infighting.
AC, the thread at the top of the page Embedding YouTube videosis a good place to start!
Splot
***Theng, Smite!
Last edited by Ascend Charlie; 21st June 2017 at 22:03. Reason: Insert YouTube link
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From: EGDC
I think we are already flying those systems - it seems it was the proving ground for semi-rigid/rigid rotors over traditional design, especially teetering head designs.
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From: Texas
For the OP:
A bit over 36 years ago, I saw a nearly identical film while in Navy Flight Training, and we were quite awed by this PR piece. Neat tech.
Here's a news flash for you. The Rotary Wing industry has not been sitting on its ass for the past 36 years. At the time, this program had much promise but as with all programs the devil is in the details, and there are competing programs, and even with Uncle Sam only so much money for the rotary wing bubbas.
If all that an aircraft had to do was be cool, all that any of us on the planet could fly would be P-51 Mustangs and F-4 Phantoms, and Cobras. There'd be no other aircraft left.
So, yeah, looks cool. There's more to it than that. And in fact, it's complicated, by at least an order of magnitude more than a fixed wing aircraft. Suggest you go and find a nice RAH-66 Comanche video and take a cup of coffee and swoon. That too was a really cool helicopter. I got to see one of the prototypes fly. Cool is an understatement.
But it didn't reach FRP for reasons.
A bit over 36 years ago, I saw a nearly identical film while in Navy Flight Training, and we were quite awed by this PR piece. Neat tech.
Here's a news flash for you. The Rotary Wing industry has not been sitting on its ass for the past 36 years. At the time, this program had much promise but as with all programs the devil is in the details, and there are competing programs, and even with Uncle Sam only so much money for the rotary wing bubbas.
If all that an aircraft had to do was be cool, all that any of us on the planet could fly would be P-51 Mustangs and F-4 Phantoms, and Cobras. There'd be no other aircraft left.
So, yeah, looks cool. There's more to it than that. And in fact, it's complicated, by at least an order of magnitude more than a fixed wing aircraft. Suggest you go and find a nice RAH-66 Comanche video and take a cup of coffee and swoon. That too was a really cool helicopter. I got to see one of the prototypes fly. Cool is an understatement.
But it didn't reach FRP for reasons.
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From: Aus
I saw a nearly identical film while in Navy Flight Training
Thread Starter
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From: Great South East, tired and retired
Wolfie, I was mainly talking about the rotor head at the start of the film, which looked to be a quantum leap over the Bell stab bars and teetering heads. Hovering hands off, and the massive control power shown by the dudes swinging on the bar were the "cool" bits, as you might say.
And yes, I understand a little about the rotary industry, having spent 45 years in it.
And yes, I understand a little about the rotary industry, having spent 45 years in it.
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From: Texas
Hmm, I'll remember not to PWD in future, that was a bit too smart assed in tone. What got me to reply at all is two things.
1. In the past two or three years, I keep seeing the -56 brought up by advocates of (fill in the blank). This was what got the "must post reflex" going ...
2. the machines they attached it to were sunk by political and inter-service infighting.
If you've been in the business 45 years, then you know as well as I do the following:
... but as with all programs the devil is in the details, and there are competing programs, and even with Uncle Sam only so much money for the rotary wing bubbas. The people buying helicopters in the late 70's early 80's, and specifically helicopters in the niche AH-56 was aiming for, were fitting together the Big 5 weapons systems that were the back bone of the Fulda Gap mind set (Blackhawk, Abrams Tank, Apache, Bradley, Patriot). And they needed to be bought in significant numbers. Political infighting? I'll offer you a different reason. COST and TIME. For full rate production you don't buy tech because "it's cool" (Oh, wait, the USAF do that all the time, sorry
). You buy it to fit a core mission requirement.
When you make something too expensive to buy and maintain in the numbers required, you don't get the order.
The reason I offered Comanche as a second example is directly linked to the above. A fine helicopter, a fine weapons system, FBW, Low Observable, some new applications of materials, a step forward in a variety of ways for the industry (Boeing and Sikorsky and others) that while it had been under threat over the money during the Clinton austerity regime eventually ran smack into TIME and MONEY as major acquisition obstacles. (IMO, Army and DoD were short sighted in that, but I am massively biased and not a neutral observer at all, not to mention I felt the Army over wrote the requirement and were unwilling to go single pilot, which would have made a significant difference ... but that's all water under the bridge)
Again, apologies to you for the tone, that was bad form.
I find the "why" that you asserted to be both unsatisfying and inaccurate.
1. In the past two or three years, I keep seeing the -56 brought up by advocates of (fill in the blank). This was what got the "must post reflex" going ...
2. the machines they attached it to were sunk by political and inter-service infighting.
If you've been in the business 45 years, then you know as well as I do the following:
... but as with all programs the devil is in the details, and there are competing programs, and even with Uncle Sam only so much money for the rotary wing bubbas. The people buying helicopters in the late 70's early 80's, and specifically helicopters in the niche AH-56 was aiming for, were fitting together the Big 5 weapons systems that were the back bone of the Fulda Gap mind set (Blackhawk, Abrams Tank, Apache, Bradley, Patriot). And they needed to be bought in significant numbers. Political infighting? I'll offer you a different reason. COST and TIME. For full rate production you don't buy tech because "it's cool" (Oh, wait, the USAF do that all the time, sorry
). You buy it to fit a core mission requirement. When you make something too expensive to buy and maintain in the numbers required, you don't get the order.
The reason I offered Comanche as a second example is directly linked to the above. A fine helicopter, a fine weapons system, FBW, Low Observable, some new applications of materials, a step forward in a variety of ways for the industry (Boeing and Sikorsky and others) that while it had been under threat over the money during the Clinton austerity regime eventually ran smack into TIME and MONEY as major acquisition obstacles. (IMO, Army and DoD were short sighted in that, but I am massively biased and not a neutral observer at all, not to mention I felt the Army over wrote the requirement and were unwilling to go single pilot, which would have made a significant difference ... but that's all water under the bridge)
Again, apologies to you for the tone, that was bad form.
I find the "why" that you asserted to be both unsatisfying and inaccurate.
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From: Earth
The program was not merely halted due to politics, the system itself had some very real issues even at the end.
The Cheyenne originally suffered from a dangerous rotor instability at high speeds that destroyed a wind tunnel asset and subsequently a flight test article and its crew.
A control system modification was derived to remedy this situation late in its history and yielded a very smooth flying machine without the stability issues above ~220 kt, however the system was extremely complex and prone to multiple independent failure modes that were catastrophic.
The Cheyenne originally suffered from a dangerous rotor instability at high speeds that destroyed a wind tunnel asset and subsequently a flight test article and its crew.
A control system modification was derived to remedy this situation late in its history and yielded a very smooth flying machine without the stability issues above ~220 kt, however the system was extremely complex and prone to multiple independent failure modes that were catastrophic.
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From: USA
The main rotor hub structure of the AH-54 was a very advanced example of titanium investment casting technology at the time.
Correction: Tough crowd. Sorry for the typo. Meant AH-56 and not AH-54.
Here is an interesting 2016 NASA report about CFD modeling and sub-scale tunnel testing of the AH-56 rotor design: http://hdl.handle.net/2060/20170000752
Correction: Tough crowd. Sorry for the typo. Meant AH-56 and not AH-54.
Here is an interesting 2016 NASA report about CFD modeling and sub-scale tunnel testing of the AH-56 rotor design: http://hdl.handle.net/2060/20170000752
Last edited by riff_raff; 26th June 2017 at 00:22. Reason: typo
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From: Hobe Sound, Florida
HI Jim. Never heard of the BH-54?
It was never called that, but an Army Ch-54 dropped one or two 10,000 lb bombs in Vietnam. True, and I believe a picture of the aircraft has been posted in Rotorheads. Idea wasn't anti-personnel, but to create a helicopter LZ in dense jungle. Apparently it knocked down a lot of trees, but left the opening with a maze of obstacles instead of the hoped for mostly cleared area.
It was never called that, but an Army Ch-54 dropped one or two 10,000 lb bombs in Vietnam. True, and I believe a picture of the aircraft has been posted in Rotorheads. Idea wasn't anti-personnel, but to create a helicopter LZ in dense jungle. Apparently it knocked down a lot of trees, but left the opening with a maze of obstacles instead of the hoped for mostly cleared area.
